Holley Power Valve possible failure

People complain that Holleys “blow a power valve” all the time. I’ve almost never seen a bad power valve unless the carb is really old and hasn’t been rebuilt in forever. Typically this is the actual problem. Now what happens is a person decides it is the power valve and they take the metering block off, replace PV, pv gasket, and metering block gasket. In doing so they have temporarily resealed the leak. The PV may still be touching the screw boss, but it’s more likely that the new gasket hasn’